Many people in the USA think that all bumblebees look pretty much alike. Yellow and black stripes. It may be surprising to learn that there are an estimated 260 bee species with more than 400 varieties of color patterns.
Now, thanks to the development of a supercomputer called Roar, which can provide the necessary computational power for gene expression studies requiring lots of data, the evolutionary genetic pathway that colors bumble bee stripes has been uncovered by scientists.
Evolution influences multiple bee species to share similar but different color patterns in particular geographic locations, so mimicry is a phenomenon that causes many people to associate bumble bees with distinct and specific colors.
Potential predators in these areas take note and are warned that they may suffer painful stings, should they proceed. Therefore, by imitating each other’s patterns and colors, multiple species teach predators to be respectful of potential consequences through color and pattern recognition.
Bees around the world create this shared warning signal by using a palette of whites, blacks, reds, oranges, and yellows.
This unrelated 6:03-minute video by Science with Mr. Harris compares bumblebees with honeybees:
Scientists are now learning more about the role of distinctive color patterns in evolutionary genetics that distinguish different bee species.
A major developmental gene that regulates the identity of structures on bee segments is called the Hox gene. It ignites a set of downstream genes that can drive segmental changes in the pigmentation of that bee, according to a study.
Heather Hines, associate professor of biology and entomology, explained that in a previous paper they were unable to explain how a change in the Hox gene Abdominal-B leads to a change in pigments that color these bees.
This paper is their attempt to fill in that gap by determining which genes are targeted by this first gene and the sequence of events that leads to these mimetic color differences.
As reported in a recent issue of Genome Biology and Evolution, the researchers discovered that altering the genomic targeting of a major developmental gene allows several melanin genes, rather than just one specific enzyme, to be altered to reinforce these color traits. The study also expands our understanding of the genes involved in the production of the pigment pheomelanin.
This pigment was recently discovered in insects. It was previously thought to be responsible for red color in vertebrates.
According to Hines, understanding the evolutionary genetics of these bees requires a lot of work. “Now that we know what these genes are, we can look at so many different bee species and see how they’ve evolved,” she said.
The team consisted of Heather M Hines, Sarthok Rasique Rahman, Tatiana Terranova, an honors undergraduate research student at Penn State, and Li Tian, former postdoctoral researcher in the Hines Lab at Penn State. The National Science Foundation supported this work.